Barack Obama nominated Kamala Harris for the presidency

Barack Obama has suggested Vice President Kamala Harris to be nominated as the Democratic Alliance president, ending days of speculation as to whether she will support him.

Former President Obama and First Lady Michelle Obama said in a joint statement that they believed Ms. Harris had “the vision, character, and energy needed at this critical time”.

Mr. Obama was reportedly among more than 100 prominent Democrats that Ms. Harris spoke to after President Joe Biden announced last Sunday that he was leaving the race.

In a statement at the time, Mr Obama praised Mr Biden's exit, but stopped short of supporting Ms Harris.

The US vice president has received the support of a majority of the Democratic Alliance delegates, putting him in a position to be officially nominated at the party's convention in August.

The Obamas said in a statement on Friday that they would be “more than happy to support” Ms Harris. They vowed to do “everything we can” to elect him.

“We agree with President Biden,” said the couple's statement, “choosing Kamala was one of the best decisions he made. He has a job to prove it.”

They cited his record as California attorney general, US senator and vice president.

“But Kamala has a lot more to her than rewriting,” the statement continued. “He has vision, character, and strength that this critical time requires.

“There is no doubt that Kamala Harris has exactly what it takes to win this election and deliver for the American people.

“At a time when the numbers have never been higher, you give us every reason to be optimistic.”

The statement was accompanied by video of Ms. Harris taking a call from the Obamas when they pledged their support.

“Oh my God,” the vice president said in the clip. “Michelle, Barack, this means a lot to me.”

Ms Harris has held several campaign events across the US in the days since Mr Biden withdrew from the race.

On Thursday, he spoke to the American Federation of Teachers in Houston.

Although the event was released as part of his duties as vice president, there was a campaign meeting, with loud applause from the audience.

Echoing language used at campaign events earlier in the week, Ms Harris focused on what she called “extremist” Republicans and “failed” policies.

“We want to ban weapons, and they want to ban books,” he said.

Meanwhile, Republican presidential nominee Donald Trump continued to attack his new rival.

On Friday evening, at the Florida conference of the conservative organization Turning Point USA, he vowed to defeat Ms Harris, calling her the most “ignorant” vice president ever.

He warned that if elected he would be “the most liberal president in American history”.

Trump has refused to commit to a televised interview with Ms. Harris until she is officially confirmed as the party's nominee.

He suggested that Democrats are “still clinging to the 'better' person”.